My long term goal is to understand the structure and regulation of eukaryotic genes. I propose to study, in the next three years, the sequence organization transcription, and biological function(s) of the intergenic DNA in the human Alpha-like globin gene cluster (human Alpha-cluster). First, we will study the relationship between the long-range sequence arrangements of the intergenic DNA and the evolution of the human Alpha-cluster. These sequence arrangements have been shown previously to be associated with the chromosomal deletion in patients with the genetic disease, Alpha-thalassemia. Secondly we propose to study the locations, nucleotide sequences, and transcription of a family of repetitive DNA (Alu family repeats) within the human Alpha-cluster. We will characterize the RNA polymerase III-dependent transcription (in vitro and in vivo) of these intergenic repeats and the interaction of the repeat transcripts with specific protein(s) to form ribonucleoprotein particles (RNPs). The nucleotide sequences of the Alpha-cluster Alu family repeats will be compared to those within the human Beta-like globin gene cluster and the repeats in the rabbit Beta-like globin gene cluster. Thirdly, we propose to study the effects of these Alu repeat transcripts or RNPs on the splicing of Alpha-globin gene transcripts. We will also test the possibility that some of these Alu family repeats in the Alpha-cluster may function as DNA replication origins in the eukaryotic cells. Fourth, we will study the transcription of non-globin, non-repeat DNA sequences of the Alpha-cluster in erythroid and non-erythroid tissues. Finally, we shall initiate the isolation by molecular cloning techniques of 50 to 100 kb long DNA regions flanking both sides of the human Alpha-cluster. The new clones will allow us to extend the above studies and provide specific probes for studying chromatin structure over a wide range of DNA flanking the Alpah-like globin genes.